For example, two-dimensional (2D) X-ray projection images of contrast enhanced vascular structures are commonly used by interventionalists to support the treatment of patients with heart disease, for example. The 2D projection images, which are also referred to as angiograms, are often used to appreciate quantities like vessel length, diameter and shape, for example. However, a true three-dimensional (3D) anatomy of the imaged vessels is lost in the angiograms which may lead to misinterpretation of the considered vessel quantities, for example. Therefore, it is known to generate a 3D representation of the vessels of interest, for example, in coronary interventions. Therefore, the vessels of interest are manually segmented in at least two angiograms which have been acquired at different viewing angles. The 3D vessel model can then be constructed from the at least two 2D segmentations using epipolar geometry. For example, US 2006/0084862 A1 describes a method including acquiring a model of a vascular system based on image data generated by an imaging device, identifying a portion of interest of the vascular system and determining a vessel axis for a vessel of interest for the reconstruction of a 3D arterial tree. However, in order to create reliable and truthful 3D vessel models, 2D segmentations from which the 3D vessel model is constructed should be as accurate as possible. This especially holds for the 2D vessel centrelines, which form the basis for the skeleton of the 3D model. Since the clinical user indicates the position of the 2D centrelines by clicking points, for example on the angiogram, which points are then used to extract an accurate shape and position of the 2D centreline from the angiogram, the possible accuracy relies on the exactness of the input by the clinical user. It has been shown that, in order to improve the accuracy of the 3D vessel model, the user has to make sure that the input is as accurate as possible which means that the interaction step is unnecessarily time consuming, what may lead to fatigue and loss of concentration which thus should be avoided.